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961.
962.
Gatti Vittorio Gelbs Michelle J. Guerra Rodrigo B. Gerber Michael B. Fritton Susannah P. 《Biomechanics and modeling in mechanobiology》2021,20(3):1135-1146
Biomechanics and Modeling in Mechanobiology - Muscle paralysis induced with botulinum toxin (Botox) injection increases vascular porosity and reduces osteocyte lacunar density in the tibial... 相似文献
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964.
Raffaele Porta Marina Camardella Vittorio Gentile Antonio De Santis 《Journal of neurochemistry》1984,42(2):321-325
Since a specific inhibition of cerebral spermidine (Spd) synthase activity by alicyclic amines was preliminarily observed in vitro, we examined the in vivo inhibitory effectiveness of dicyclohexylamine (DCHA) on Spd biosynthesis in 21-day-old rat brain. For this purpose a previously reported HPLC procedure (Porta et al., 1981a) was modified to analyze the cerebral levels of DCHA at the time of polyamine determinations. The intraperitoneally injected DCHA was shown to cross the blood-brain barrier easily, reaching high levels in the cerebral tissue (approximately 750 nmol/g brain) within 1 h of its administration. The effect of the drug on the polyamine metabolism resulted in a significant depletion of Spd biosynthesis from the sixth hour after the treatment and in an earlier and prolonged increase of the putrescine (Pt) steady-state levels. Conversely, the spermine (Spm) endogenous pools remained unchanged throughout the 24-h post-DCHA period. Moreover, following the intracerebral administration of [1,4-14C]Pt, significantly lower specific radioactivity (s.r.a.) values for labeled Pt and Spd were recorded in the brains of DCHA-treated animals. Conversely, after intracerebral [14C]Spd injection, the s.r.a. of newly formed [14C]Spm remained unchanged, confirming the specificity of the DCHA effect on the Spd biosynthesis. 相似文献
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967.
Tongue movements during speech production have been investigated by means of a simple yet realistic biomechanical model,
based on a finite elements modeling of soft tissues, in the framework of the equilibrium point hypothesis (-model) of motor control. In particular, the model has been applied to the estimation of the “central” control commands issued
to the muscles, for a data set of mid-sagittal digitized tracings of vocal tract shape, r
ecorded by means of low-intensity X-ray cineradiographies during speech. In spite of the highly non-linear mapping between
the shape of the oral cavity and its acoustic consequences, the organization of control commands preserves the peculiar spatial
organization of vowel phonemes in acoustic space. A factor analysis of control commands, which have been decomposed into independent
or “orthogonal” muscle groups, has shown that, in spite of the great mobility of the tongue and the highly
complex arrangement of tongue muscles, its movements can be explained in terms of the activation of a small number of independent
muscle groups, each corresponding to an elementary or “primitive” movement. These results are consistent with the hypothesis
that the tongue is controlled by a small number of independent “articulators”, for which a precise biomechanical substrate
is provided. The influence of the effect of jaw and hyoid movements on tongue equilibrium has also bee
n evaluated, suggesting that the bony structures cannot be considered as a moving frame of reference, but, indeed, there may
be a substantial interaction between them and the tongue, that may only be accounted for by a “global” model. The reported
results also define a simple control model for the tongue and, in analogy with similar modelling studies, they suggest that,
because of the peculiar geometrical arrangement of tongue muscles, the central nervous system (CNS) may not need a de
tailed representation of tongue mechanics but rather may make use of a relatively small number of muscle synergies, that are
invariant over the whole space of tongue configurations.
Received: 27 August 1996 / Accepted in revised form: 25 February 1997 相似文献
968.
Marisa Berti Roberto Scotti Franca Ripamonti Vittorio Arioli 《Current microbiology》1979,2(4):223-225
The activity of the combination rifampin plus trimethoprim againstHaemophilus influenzae was studied from the point of view of synergism, bactericidal activity, and inhibition of the selection of rifampin-resistant
cells. At concentrations of the two drugs that are easily attainable in human serum after oral treatment with 600 mg of rifampin
plus 160 mg of trimethoprim, the combination acted synergistically on all of the strains tested, was remarkably bactericidal,
and inhibited the selection of rifampin-resistant cells. 相似文献
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970.
Matteo Scopetti Alessandro Santurro Vittorio Gatto Raffaele La Russa Federico Manetti Stefano D’Errico Paola Frati Vittorio Fineschi 《World journal of stem cells》2020,12(3):168-177
The treatment of neurodegenerative diseases presents a growing need for innovation in relation to recent evidence in the field of reconstructive therapy using stem cells. Understanding the molecular mechanisms underlying neurodegenerative disorders, and the advent of methods able to induce neuronal stem cell differentiation allowed to develop innovative therapeutic approaches offering the prospect of healthy and perfectly functional cell transplants, able to replace the sick ones. Hence the importance of deepening the state of the art regarding the clinical applications of advanced cell therapy products for the regeneration of nerve tissue. Besides representing a promising area of tissue transplant surgery and a great achievement in the field of neurodegenerative disease, stem cell research presents certain critical issues that need to be carefully examined from the ethical perspective. In fact, a subject so complex and not entirely explored requires a detailed scientific and ethical evaluation aimed at avoiding improper and ineffective use, rather than incorrect indications, technical inadequacies, and incongruous expectations. In fact, the clinical usefulness of stem cells will only be certain if able to provide the patient with safe, long-term and substantially more effective strategies than any other treatment available.The present paper provides an ethical assessment of tissue regeneration through mesenchymal stem cells in neurodegenerative diseases with the aim to rule out the fundamental issues related to research and clinical translation. 相似文献